Compressed air is commonly used to perform a myriad of functions. For example, compressed air may be used to displace water in submarine ballast tanks to increase the buoyancy of the submarine, to operate brakes on locomotives and trucks, or to pneumatically operate valves. In each case, the compressed air may include moisture and other particulate contaminates which, if not removed, may accelerate fouling, corrosion, and other interference with the equipment.
Various air dryers are known in the art to remove moisture and particulate contaminates from the compressed air. The air dryers typically include various combinations of filters and moisture separators to clean and dry the compressed air before it reaches the equipment. For equipment that requires a continuous supply of compressed air, the air dryers may include duplicate flow paths arranged in parallel so that one flow path may purify the compressed air while the other flow path is purged of the filtered moisture and particulates. However, previous air dryer designs may be susceptible to reduced effectiveness and/or complete failure in the event of improper valve alignment. Therefore, an improved air dryer that may continue to operate and supply compressed air in spite of a failed or misaligned valve would be useful.